ULTIMATE COMPUTING - Quantum Consciousness Studies

138 Protein Conformational Dynamics
non-polar, that is they have no charge-like polar groups to form hydrogen bonds
in water) tend to combine, or coalesce for two main reasons: Van der Waals
forces and exclusion of water. Combination of hydrophobic groups “liberate”
ordered water into free water, resulting in increased entropy and decreased free
energy, factors which tend to drive reactions. The magnitude of the favorable free
energy change for the combination of hydrophobic groups depends on their size
and how well they fit together “sterically.” A snug fit between groups will
exclude more water from hydrophobic regions than will loose fits. Consequently,
specific biological reactions can rely on hydrophobic interactions. Forma, tion of
tertiary and quaternary protein structure (including the assembly of microtubules
and other cytoskeletal polymers) are largely regulated by hydrophobic
interactions, and by the effect of hydrophobic regions on the energies of other
bonding. A well studied example of the assembly of protein subunits into a
complex structure being accompanied by an increase in entropy (decrease in
order) is the crystallization of the tobacco mosaic virus. When the virus assembles
from its subunits, an increase in entropy occurs due to exclusion of water from the
virus surface. Similar events promote the assembly of microtubules and other
cytoskeletal elements.
Figure 6.4: Microtrabecular lattice (MTL-solid dark) with layers of ordered and
vicinal water. “Soluble” enzymes (circles) are held within ordered or “vicinal” water
and may be functionally regulated by the MTL. Modified from Clegg (1984) by
Paul Jablonka.